Correct Option
The correct option is Density of the material increases with depth.
Explanation
The Earth is differentiated into concentric layers-Crust, Mantle, and Core-based on physical and chemical properties. A fundamental characteristic of this structure is that the density of materials changes progressively from the surface to the center due to gravitational differentiation (heavier elements sinking) and the immense pressure exerted by overlying layers.
Option Analysis
- Density decreases with increasing distance from Density does not decrease with distance from the surface; it increases. The lightest materials are found at the surface, while the heaviest are concentrated at the center.
- Density remains constant throughout the mantle. is Incorrect: Density does not remain constant within the mantle. It increases from the upper mantle (approximately 3.4 g/cm³) to the lower mantle (approximately 5.5 g/cm³) due to increasing pressure and mineral phase changes.
- Density of the material increases with depth. is Correct: The density of Earth's material increases with depth. The average density ranges from roughly 2.7 g/cm³ in the continental crust to nearly 13 g/cm³ in the inner core.
- The crust has the highest density among all layers. is Incorrect: The crust is the least dense layer (2.7-3.0 g/cm³). The core is the densest layer, composed primarily of heavy metals like Nickel and Iron (NIFE).
Key Takeaway: The density of Earth increases with depth, starting from the least dense silicate Crust and reaching the highest density in the metallic Core, driven by chemical composition and pressure.